Double Injection Locking Active Antenna

A technique for phase noise improvement using double injection locking oscillator is presented in this paper. Two oscillators are used in the system. The output of the first oscillator is connected to an antenna. The output of the second oscillator is injected into the first oscillator. The feedback loop is created by coupling the output signal at the antenna via another antenna connected to the injection port of the second oscillator. It is shown in the experiment that the phase noise of the signal is better than the oscillator with external injection signal. Furthermore, spurious frequencies in the spectrum are reduced. This technique may be used to improve the phase noise and spurious frequency in the active antennas.